1. Field of the Invention
The present invention is related to a video endoscope, and in particular to a video endoscope having a strobe lamp for phase-synchronous stroboscopic illumination of an examination subject.
2. Related Application
The present application is related to the co-pending application of Reiner Hoffman and Peter Jaggy entitled "Circuit For A Flash Stroboscope For Examining Vocal Chord Functions" filed Oct. 10, 1986 and having Ser. No. 917,692, assigned to the assignee of the present application.
3. Description of the Prior Art
Video endoscopes, sometimes called video technoscopes, are optical devices used to observe the interior of an examination object through exterior openings therein, wherein the image is "seen" by an optical system, with the output of the optical system being forwarded by a video system for reproduction on the picutre screen of a monitor.
In medical applications, for example, laryngoscopy or epilaryngoscopy, such video endoscopes are used for observing internal organs of a human or animal examination subject.
Under such circumstances, the object under examination is generally illuminated with continuous light generated by a light source, the light being conducted to the examination subject by optical fibers.
Stroboscopic examination are also possible wherein a vibrating member, for example, the vocal cords, is illuminated with phase-synchronized flashes thus rendering the periodic sequences visible. Deviations from normal vibrational behavior due, for example, to organic changes, diseases, injuries or the like can be identified by this method, so that the necessary therapy can be prescribed.
Endoscopes are known which provide for changing from continuous illumination by, for example, a pilot lamp, to stroboscopic illumination by a phase-synchronously controllable strobe lamp. The endoscope described in German OS No. 20 14 662 provides a beam deflection means with which the continuous light of the pilot lamp or the strobe lamp of the electronic flash device can be alternatively supplied to the light guide.
The structural components and, more importantly, the space requirements for such endoscopes are relatively high due to the use of two different light sources.